Patterned turbomachine component and method of forming a pattern on a turbomachine component

ABSTRACT

A method of forming a pattern on a turbomachine component includes adding material to selected surface regions of the turbomachine component, the material is arranged in a predetermined pattern.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to the art of turbomachinesand, more particularly, to a patterned turbomachine component and amethod of forming a pattern on a turbomachine component.

Turbomachine components, such as compressor blades, rotate to generate ahigh pressure air flow. The high pressure air flow combines with acombustion air flow to rotate turbine blades. Changes in aerodynamicproperties of either the compressor blades and/or the turbine bladesresult in changes to overall operational characteristics of theturbomachine. It has been found that increasing a surface area ofcompressor and/or turbine blades leads to enhanced turbomachineoperation.

Conventional methods of increasing surface area of compressor and/orturbine blades include molding processes and etching or machining, i.e.,surface removal, processes. In the molding process, patterns are formedon a mold. When cast, the patterns are formed on a surface of thecompressor and/or turbine blades. The patterns are configured anddisposed to increase an effective surface area and enhance aerodynamicproperties of the compressor and/or turbine blades. In the etchingprocess, chemicals, lasers or other methods are employed to removespecific portions from the surface of the compressor and/or turbineblades. As noted above, the patterns are configured and disposed toincrease an effective surface area and enhance aerodynamic properties ofthe compressor and/or turbine blades.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the invention, a method of forming a patternon a turbomachine component includes adding material to selected surfaceregions of the turbomachine component, the material is arranged in apredetermined pattern.

According to another aspect of the invention, a turbomachine componentincludes a body portion having an external surface. A pattern is formedon the external surface. The pattern includes material added to theexternal surface through a direct write (DW) process.

System and computer program products for adding material to selectedregions of a turbomachine component are also described and claimedherein.

These and other advantages and features will become more apparent fromthe following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWING

The subject matter, which is regarded as the invention, is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other features, and advantages ofthe invention are apparent from the following detailed description takenin conjunction with the accompanying drawings in which:

FIG. 1 is a partial, cross-sectional view of a turbomachine including apatterned turbomachine component in accordance with an exemplaryembodiment;

FIG. 2 is a perspective view of the patterned turbomachine component ofFIG. 1;

FIG. 3 is a partial side view of the patterned turbomachine component ofFIG. 2 illustrating material added to a surface of the turbomachinecomponent to form a pattern;

FIG. 4 is a flow chart illustrating a method of forming a pattern on aturbomachine component in accordance with an exemplary embodiment; and

FIG. 5 is a plan view of another patterned turbomachine component inaccordance with an exemplary embodiment.

The detailed description explains embodiments of the invention, togetherwith advantages and features, by way of example with reference to thedrawings.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a turbomachine constructed in accordance with anexemplary embodiment is indicated generally at 2. Turbomachine 2includes a turbine casing 4 that houses a combustion chamber 6 and aturbine stage 8. In the exemplary embodiment shown, turbine stage 8 is afirst stage. Combustion gases from combustion chamber 6 pass through afirst stage nozzle 10 along a hot gas path (HGP) 12 to a second stagenozzle 14. The combustion gases drive a rotor disk 20 that, in turn,drives a turbine shaft (not shown). Rotor disk 20 is arranged in a wheelspace area 22 of turbomachine 2 and includes a plurality of turbinebuckets, one of which is indicated at 24, mounted to rotor disk 20. Eachturbine bucket 24 includes a body portion 27 that defines a base portion30, and an airfoil portion 32. Airfoil portion 32 includes a first endsection 34 that extends to a second end section 35 through an airfoilsurface 38. The combustion gases passing along hot gas path 12 impactairfoil surface 38 pushing airfoil portion 32 circumferentially causingrotor disk 20 to rotate.

In accordance an exemplary embodiment, airfoil surface 38 includes apatterned zone 47 having a plurality of raised elements, one of which isindicated at 54 that enhance aerodynamic performance for turbine bucket24. Each raised element 54 includes a body portion 57 having a baseportion 59 that extends to a tip portion 61. Although shown having agenerally trapezoidal form with base portion 59 being larger than tipportion 61, it should be understood that raised element 54 can take on avariety of forms, including forms having rectangular profiles,curvilinear profiles and the like. In accordance with one aspect of theexemplary embodiment, a coating is applied to patterned zone 47. Coating65 provides additional protection for each raised element 54. In theexemplary embodiment shown, coating 65 is applied in a substantiallylinear layer. However, it should be understood that coating 65 couldalso be contoured. In accordance with another aspect of the exemplaryembodiment, a plurality of pores 69 are created in body portion 57.Pores 69 further enhance the surface area of raised elements 54.

In further accordance with the exemplary embodiment, patterned zone 47is formed using a direct right (DW) process. The direct right processadds material to airfoil surface 38 in a predetermined pattern. Inaccordance with one aspect of the exemplary embodiment, raised elements54 are formed from at least one of a polymer, a ceramic, a metal, and acomposite. Of course other materials and composites may also beemployed. As will be discussed more fully below, depending upon thematerial employed for raised elements 54, prior to adding patterned zone47, a bond coat 78 is applied to airfoil surface 38. Bond coat 78enhances adhesion of the plurality of raised features 54 that are addedusing the DW process.

Reference will now be made to FIG. 4 in describing a method 90 ofcreating patterned zone 47. Initially, a pattern design and materialtype is formulated for the DW process as indicated in block 92. That is,prior to creating patterned zone 47, the particular type of pattern andthe particular material employed to form the pattern is formulated andinput into a DW process application. In accordance with one aspect, theparticular material(s) chosen will result in raised elements 54including pores 69. At this point, if required, bond coat 78 is added toairfoil surface 38 as indicated in block 94. After applying bond coat 78and/or grit blasting or chemical etching is applied to improve surfaceroughness to enhance adhesion, surface deposits are added to airfoilsurface 38 as indicated in block 96. After adding the surface depositsto form the plurality of raised features 54, airfoil surface 38 isheat-treated to consolidate or harden raised features 54 as indicated inblock 98. Of course, it should be understood that the need forheat-treatment is dependent upon the particular type of material used informing the plurality of raised features.

After heat-treating, a partial overcoat is applied to the plurality ofraised features 54 as indicated in block 100. The overcoat or coating isused to provide additional protection to the plurality raised featuresas indicated above. Of course the need for an overcoat or coating isalso dependent on a particular type of material used in formingpatterned zone 47. In addition to adding features, material may beremoved to form additional patterns in airfoil surface 48. The materialis removed using one or more known techniques such as etching, lasersand the like.

At this point, it should be understood that the exemplary embodimentsemploys a direct write (DW) process to add material to surface portionsof a turbomachine component to form a patterned zone. Of course, onceadded, portions of the material can be selectively removed toalter/adjust the patterned zone. If desired, the material is selectivelyremoved using a solvent to dissolve portions of the patterned zone, orusing a laser to remove/alter portions of the patterned zone. Inaddition to providing patterns on three-dimensional (3D) surfaces suchas turbine buckets described above, exemplary embodiments can beemployed to create a patterned zone 110 on two-dimensional (2D) surfacessuch as a shroud 120 shown in FIG. 5. Regardless of the surface, theadditional material enhances the structural stability of theturbomachine component. That is, instead of the conventional process forcreating patterns on existing turbomachine components which requiresremoving material, the exemplary embodiments add material to theturbomachine component to enhance aerodynamic properties.

While the invention has been described in detail in connection with onlya limited number of embodiments, it should be readily understood thatthe invention is not limited to such disclosed embodiments. Rather, theinvention can be modified to incorporate any number of variations,alterations, substitutions or equivalent arrangements not heretoforedescribed, but which are commensurate with the spirit and scope of theinvention. Additionally, while various embodiments of the invention havebeen described, it is to be understood that aspects of the invention mayinclude only some of the described embodiments. Accordingly, theinvention is not to be seen as limited by the foregoing description, butis only limited by the scope of the appended claims.

1. A method of forming patterns on a turbomachine component, the methodcomprising: adding material to selected surface regions of theturbomachine component using a direct write (DW) process, the materialbeing arranged in a predetermined pattern.
 2. The method of claim 1,wherein adding material to the selected surface regions includes addingat least one of a two-dimensional structure and a three-dimensionalstructure to the selected surface regions.
 3. The method of claim 1,further comprising: creating a computer drawing file that defines thepredetermined pattern to be added to the selected surface regions of theturbomachine component.
 4. The method of claim 3, further comprising:transferring the pattern directly to the turbomachine component.
 5. Themethod of claim 1, further comprising: adding material with at least oneof a nozzle dispensing process, thermal spray process, a softlithography process, and a laser process.
 6. The method of claim 1,further comprising: removing a portion of the material added to theselected surface regions.
 7. The method of claim 6, wherein removing theportion of the material includes dissolving, with a laser, predeterminedportions of the material.
 8. The method according to claim 1, whereinthe material is added to select surface regions of one of a compressorblade and a turbine blade.
 9. A system for establishing a pattern on aturbomachine component, the system comprising: a central processing unit(CPU), said CPU being interconnected functionally via a system bus to:at least one memory device thereupon stored a set of instructions which,when executed by the CPU, causes the system to: add material to selectedsurface regions of the turbomachine component using a direct write (DW)process, the material being arranged in a predetermined pattern.
 10. Thesystem according to claim 9, wherein the set of instructions, whenexecuted by the CPU, causes the system to: add at least one of atwo-dimensional structure and a three-dimensional structure to theselected surface regions.
 11. The system according to claim 9, whereinthe set of instructions, when executed by the CPU, causes the system to:transfer a pattern stored in the at least one memory device directly tothe turbomachine component.
 12. The system according to claim 9, whereinthe set of instructions, when executed by the CPU, causes the system to:add material through a direct write (DW) process.
 13. The systemaccording to claim 12, wherein the set of instructions, when executed bythe CPU, causes the system to: add material with at least one of anozzle dispensing process, miniature gun thermal spray process, a softlithography process, and a laser process.
 14. The system according toclaim 9, wherein the set of instructions, when executed by the CPU,causes the system to: remove a portion of the material added to theselected surface regions.
 15. A turbomachine component comprising: abody portion including an external surface; and a pattern formed on theexternal surface, the pattern including material added to selectportions of the external surface through a direct write (DW) process.16. The turbomachine according to claim 15, further comprising: removinga portion of the material added to the select portions of the externalsurface.
 17. The turbomachine according to claim 15, wherein theturbomachine component includes a three-dimensional (3D) surface. 18.The turbomachine according to claim 17, wherein the turbomachinecomponent is one of a compressor blade and a turbine blade.
 19. Theturbomachine according to claim 15, wherein the turbomachine componentincludes a two-dimensional (2D) surface.
 20. The turbomachine accordingto claim 19, wherein the turbomachine component is a shroud.